The present invention relates to a non-volatile memory device.
Due to their favorable mobility, shock resistance, etc., the demand for non-volatile memory devices has been growing rapidly in recent years as memory devices for such compact mobile information devices as mobile personal computers, digital still cameras, etc. In order for the market for such compact devices to grow, increasing the density of memory devices as well as reducing their costs become vital. Accordingly, various memory cell systems have been proposed to these ends.
Currently, the most popular memory cell system is the flash memory. However, the size reduction technology thereof is approaching its limit, and as a non-volatile memory device to take its place, resistive random-access memory, which is one of the memory cell systems mentioned above, is under development.
JP Patent Application Publication (Kokai) No. 2008-160004 A (Patent Document 1) discloses a resistive random-access memory device in which a plurality of memory cells are connected in series and perpendicularly to the main surface of a substrate. The memory cells are structured in such a manner that a transistor, which is a select element, and a phase-change film, which is a storage element, are connected in parallel, and a gate insulator film, a channel silicon film, a barrier film, and a phase-change film are buried in a hole that penetrates a structure in which gates and insulator films are alternately stacked.